I think this female is infertile since it is quite a long time together with the male (they were in the same indoor enclosure), I think they are already 2 years together. I think the male was sent with the hope to breed with the female, or I am wrong (It was sent just to make company to her)? The Belgrade zoo was stubborn and was not sending anywhere its female, so a male was sent in the zoo.
@Nikola Chavkosk He was sent after Dvur Kravlove stopped breeding. They had 2 females; Vanja and Sanja. Sanja died in the 1990's, so Vanja was on her own for 15 years. Presumably, it is just for company as Elmer is no longer needed for breeding and it is likely as you say, Vanja is unfertile.
